There are many memory-related conditions for which therapeutic treatments are under investigation, such as methods to enhance memory or to treat memory dysfunction. For example, memory dysfunction is linked to the aging process, as well as to neurodegenerative diseases such as Alzheimer's disease. Also, memory impairment can follow head trauma or multi-infarct dementia. Many compounds and treatments have been investigated which can enhance cognitive processes, that is, which can improve memory and retention.
The compound piracetam has been prescribed for treatment to enhance memory [Giurgea et al, Arch. Int. Pharmacodyn. Ther., 166, 238 (1967)]. U.S. Pat. No. 4,639,468 to Roncucci et al describes the compound milacemide which is mentioned as useful for treatment of memory troubles. Further investigations of milacemide have documented the memory-enhancing capabilities of milacemide in human subjects [B. Saletu et al, Arch. Gerontol. Geriatr., S, 165-181 (1986)].
Other compounds having effects on the Central Nervous System (CNS) have been investigated. For example, the compound D-cycloserine, in its D- and L-isomer forms, has been evaluated for effects on the upper region of the CNS [O. Mayer et al, Arzneim. Forsch., 21(2), 298-303 (1971)]. These cycloserine isomers have also been evaluated for psychological and physiological effects in healthy human subjects [M. Vojtechovsky, Act. Nerv. Super., 7(3), 269 (1965); V. Vitek et al, Psychopharmacologia, 7(3), 203-219 (1965)].